The overall goal of our research has been to identify markers or reliable patterns of markers of vulnerability to alcoholism. Utilizing a research design that required families to be ascertained through two alcoholic brothers has enabled us to collect marker data for families exhibiting a severe form of alcoholism (early onset, multiple affected relatives). The research has concentrated on obtaining both clinical and laboratory measures for nuclear families of probands identified through treatment centers and extensive clinical information about the extensive pedigrees of these families (average pedigree contains 30 individuals). Marker data from three generations: proband and siblings, his parents, his children and siblings' children have revealed some intriguing results. We plan to further specify the mode of transmission of alcoholism through the enlargement of our core sample to include 50 new families. In addition, we plan to refine our studies of markers (information processing characteristics, particularly auditory and visual event-related potentials, and cardiac activity in varying tasks), and assessment of temperament and clinical diagnosis. Segregation analysis of diagnosed alcoholism within families will bc performed for these new families as a reliability check, and the families combined to improve our ability to differentiate between competing transmission models. Secondly, we plan to pursue the relationship between temperament and attentional processing capacity in young children. Third, we plan to build the foundation for a comprehensive prospective longitudinal follow-up of children between the ages of 8-13 years.